Sensory-motor relationships in speech production in post-lingually deaf cochlear-implanted adults and normal-hearing seniors: Evidence from phonetic convergence and speech imitation Lucie Scarbel, Denis Beautemps, Jean-Luc Schwartz, Marc Sato To cite this version: Lucie Scarbel, Denis Beautemps, Jean-Luc Schwartz, Marc Sato. Sensory-motor relationships in speech production in post-lingually deaf cochlear-implanted adults and normal-hearing seniors: Evi- dence from phonetic convergence and speech imitation. Neuropsychologia, Elsevier, 2017, Neuropsy- chologia, 101, pp.39 - 46. 10.1016/j.neuropsychologia.2017.05.005. hal-01546755 HAL Id: hal-01546755 https://hal.archives-ouvertes.fr/hal-01546755 Submitted on 26 Jun 2017 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Running head: SENSORY-MOTOR RELATIONSHIPS IN CI AND ELDERLY ADULTS 1 Sensory-motor relationships in speech production in post-lingually deaf cochlear- implanted adults and normal-hearing seniors: evidence from phonetic convergence and speech imitation Lucie Scarbel 1, Denis Beautemps 1, Jean-Luc Schwartz 1, & Marc Sato 2 1 GIPSA-LAB, Département Parole & Cognition, CNRS & Grenoble Université, Grenoble, France 2 Laboratoire Parole & Langage, CNRS & Aix-Marseille Université, Aix-en-Provence, France Authors’ note: Correspondence can be addressed to Lucie Scarbel, GIPSA-LAB, UMR CNRS 5216, Grenoble Université, Domaine Universitaire, BP 46, 38402 Saint Martin d’Hères, France. Tel: (+33) (0)476 824 128. Fax: (+33) (0)476 574 710. Email: [email protected]. The authors declare no competing financial interests. Running head: SENSORY-MOTOR RELATIONSHIPS IN CI AND ELDERLY ADULTS 2 SENSORY-MOTOR RELATIONSHIPS IN CI AND ELDERLY ADULTS 3 Abstract: Speech communication can be viewed as an interactive process involving a functional coupling between sensory and motor systems. One striking example comes from phonetic convergence, when speakers automatically tend to mimic their interlocutor’s speech during communicative interaction. The goal of this study was to investigate sensory-motor linkage in speech production in postlingually deaf cochlear implanted participants and normal hearing elderly adults through phonetic convergence and imitation. To this aim, two vowel production tasks, with or without instruction to imitate an acoustic vowel, were proposed to three groups of young adults with normal hearing, elderly adults with normal hearing and post-lingually deaf cochlear-implanted patients. Measure of the deviation of each participant’s f0 from their own mean f0 was measured to evaluate the ability to converge to each acoustic target. Results showed that cochlear-implanted participants have the ability to converge to an acoustic target, both intentionally and unintentionally, albeit with a lower degree than young and elderly participants with normal hearing. By providing evidence for phonetic convergence and speech imitation, these results suggest that, as in young adults, perceptuo-motor relationships are efficient in elderly adults with normal hearing and that cochlear-implanted adults recovered significant perceptuo-motor abilities following cochlear implantation. Key-words: Phonetic convergence, imitation, cochlear implant, elderly, sensory-motor interactions, speech production SENSORY-MOTOR RELATIONSHIPS IN CI AND ELDERLY ADULTS 4 1 1. Introduction 2 1.1. Sensory-motor interactions in speech perception and speech production 3 In the speech communication domain, an old and fundamental debate concerns the nature of processes 4 and representations involved in speech perception and production. Concerning speech perception, 5 auditory theories assume that speech perceptual processing and categorization are based on acoustic 6 features and auditory representations (Stevens and Blumstein 1978, 1979; Lindblom et al. 1988, 1990). 7 Conversely, the motor theory of speech perception (Liberman et al., 1985) or the direct realist theory 8 (Fowler, 2005) respectively claim that speech perception involves the recovery of the speaker’s motor 9 intentions or articulatory gestures. More recently, various perceptuo-motor theories introduced 10 syntheses of arguments by tenants of both auditory and motor theories, and proposed that implicit 11 motor knowledge and motor representations are used in relationship with auditory representations and 12 processes to elaborate phonetic decisions (Skipper et al., 2007; Schwartz et al., 2012). These theories 13 capitalize on the increasing amount of evidence for the role of motor representations and processes in 14 speech perception (see a recent review in Skipper et al., 2017). 15 Concerning speech production, various theories have also been introduced to characterize the 16 speaker’s goals. Motor or articulatory theories, like Task dynamics (Saltzman, 1986) and the 17 associated Articulatory Phonology (Browman & Goldstein, 1992), consider that speech targets are 18 defined in the articulatory space. On the contrary, auditory theories like Stevens’ Quantal Theory 19 (Stevens 1972, 1988) and Perkell’s speech production control model (Perkell et al. 1995, 2000), 20 suggest that targets are specified in auditory terms. Finally, sensory-motor models claim that speech 21 production control is multimodal and combines auditory and somatosensory information (see Perrier, 22 2005; and the DIVA model, Guenther et al. 1998, Guenther & Vladusich, 2012). A number of data 23 about the effect of auditory (e.g. Lametti et al., 2014; Shiller & Rochin, 2014) or somatosensory 24 (Tremblay et al., 2003) perturbations applied to speech production in adults or children are in 25 agreement with this sensory-motor framework. SENSORY-MOTOR RELATIONSHIPS IN CI AND ELDERLY ADULTS 5 26 From a number of these theories, sensory-motor relationships seem to play an important role in 27 both speech perception and speech production in normal conditions. The present study deals with 28 subjects for which some degradation of the sensory-motor link could be expected, because of sensory 29 deficits. The first and primary situation is the case of post-lingually deaf subjects equipped with 30 cochlear implants. Indeed, post-lingually deaf subjects are expected to have acquired efficient sensory- 31 motor relationships before deafness. Their ability to achieve intelligible speech production is 32 interpreted as evidence that they have maintained a stable and rather accurate internal model of these 33 sensory-motor relationships all along their deafness life (Perkell et al., 2000). Cochlear implantation 34 then results in providing them with a new kind of auditory input, quite different from the one they had 35 acquired before deafness considering the very special nature of cochlear-implant coding of acoustic 36 information. The question is to know how the internal relationships between these “new” auditory 37 inputs, the “old” ones acquired at the first stages of development, and the motor representations are 38 established and organized, and how efficient they are. 39 A number of data on speech production after cochlear implantation display an increase in acoustic 40 dispersion of vowels after a few months of implantation (e.g. Langereis et al., 1998; Lane et al., 2005; 41 Ménard et al., 2007), suggesting that the internal model has indeed benefited from the new auditory 42 input provided by cochlear implantation. Interestingly however, some studies explored the response to 43 articulatory perturbation using a bite-block task (Lane et al., 2005), a robotic device displacing the jaw 44 during speech (Nasir & Ostry, 2008) or a lip-tube task (Turgeon, Prémont, Trudeau-Fisette, & Ménard, 45 2015), with or without auditory feedback. Results showed that post-lingual cochlear-implanted 46 participants (CI) are able to adapt their articulatory trajectory when it is perturbed in order to reach 47 their auditory goals and make their production intelligible, even when the implant is turned off. Such 48 compensatory strategies show that perceptuo-motor abilities acquired during speech acquisition in CI 49 subjects are still at work after deafness, though the addition of auditory information provided by the 50 cochlear-implant does result in enhanced precision and efficiency of the sensory-motor internal model. 51 Finally, a PET-scanning study on visual speech perception in post-lingually deaf CI patients (Rouger 52 et al., 2012) showed that after a short adaptation period with the implant, there was a decrease of the SENSORY-MOTOR RELATIONSHIPS IN CI AND ELDERLY ADULTS 6 53 initially abnormal activity in the superior temporal sulcus, a cross-modal brain area, accompanied by a 54 progressive reactivation of frontal premotor speech areas. This suggests that sensorimotor 55 neuroplasticity after cochlear implantation provides a progressive reactivation of the audio-visuo- 56 motor linkage in CI subjects. 57 The second situation considered in the present study is the case of elderly subjects. They are of 58 interest for us for two reasons. The first one is the interest of assessing the consequences